An ambient network is a digital environment that is sensitive, adaptive, and responsive to the presence of people. In the context of wireless communications, an ambient network is a communication network that automatically responds and adapts to the needs of each particular user, such as the user of a mobile terminal (e.g. mobile telephone or mobile-equipped laptop computer) or a private area network (PAN). As one example, if a user switches a mobile telephone call from voice to video transmission, the ambient network automatically detects the switch, identifies the optimal wireless communication network for handling the video transmission based on the current location of the user, and then switches communication technology on behalf of user so as to improve bandwidth or reduce cost. For instance, the ambient network may automatically switch among wireless technologies such as Global System for Mobile Communications (GSM) technologies, Universal Mobile Telecommunications Systems (UMTS) employing wideband code-division multiple access (WCDMA) technologies, Super Third Generation (S3G) technologies, Wide Local Area Network (WLAN) technologies, BlueTooth technologies and Worldwide Interoperability for Microwave Access (WiMAX) technologies. As another example, if the user wishes to print a document from a mobile-equipped laptop computer, the ambient network automatically identifies the nearest available printer and routes the document to that printer, converting the format if needed.
As a matter of terminology, individual user terminals or individual PANs are typically referred to as a Mobile Ambient Networks (MANs). Hence, it should be understood that the concept of the MAN includes individual user terminals, such as individual mobile telephones, and therefore the MAN is not limited to what is conventionally regarded as a network. The ambient communication networks that interact with the MANs to provide ambient access are typically referred to as Access Ambient Network (AANs). The AANs incorporate, or interface with, otherwise conventional Radio Access Technology (RAT) networks such as GSM, UMTS, etc. Ambient networks and related technologies are discussed in publicly available documents provided by the Ambient Networks organization, which is an integrated project co-sponsored by the European Commission under the Information Society Technology priority under the 6th Framework Programme. In particular, see Technical Annex to D3.2 “Connecting Ambient Networks-Architecture Protocol Design,” (Document No. IST-2002-507134-AN/WP3/D3.2/TA, 31 Mar. 2004).
Significant problems arise when attempting to implement a true ambient network. In particular, a tremendous amount of signaling may be required between each user terminal or PAN and the ambient networks with which they communicate. This is particularly true if the user wishes to maintain some degree of control over the networks that are utilized. Conventionally, a user has an agreement with one particular operator/network and this operator negotiates on behalf of the user before handing over the user to a different operator. This is typically the case when roaming among the multiple networks. However, with ambient networks, it is anticipated that the user will have relations with many operator/networks and may wish to be more actively involved in the network access selection process. For example, the user may not trust any given operator to act in the best interests of the user or the user may wish to tailor the network selection process in a way that any single existing operator/network does not support. As a result, a substantial amount of “negotiation” signaling may be required between each MAN and the various AANs to accommodate and coordinate network selection on behalf of each MAN. The negotiation signaling may pertain, for example, to establishing trust, billing, and security relationships between the MAN and the AANs, including transference of Authentication, Authorization, Accounting (AAA) credentials. The negotiation signaling may also pertain to negotiations among different AANs or between a given AAN and otherwise conventional network operators of GSM, UMTS, etc., systems.
The negotiation signaling is in addition to the typical sort of handover signaling required to handover a mobile terminal from one network to another having a predetermined trust relationship. Accordingly, the additional negotiation signaling vastly increases the required bandwidth, particularly between the MANs and the AANs, which rely on wireless communication channels. Moreover, significant signaling delays can arise. In many cases, the available wireless communication bandwidth between the MANs and the various AANs is not sufficient to accommodate the additional negotiation signaling, and so it is simply not feasible to implement a true ambient network, at least not one allowing users to retain much control over network selection.
Hence, there is a significant need to provide improved techniques for handling negotiation signaling within ambient networks and it is to this end the invention is primarily directed.